Devices
The Windows window lists the name (it starts as the Android model and you can edit it), the IP, the approximate region, last seen, and whether it is online. If the tunnel does not send an IP, the list shows “unknown”.
GROK BUILD · ANDROID · WINDOWS
cBuildRemote
Your PC’s Grok Build, on the phone.
A free Android app and a Windows installer. The PC must already have Grok Build installed and signed in. Without that, the Windows app does not open sessions, folders, or PowerShell windows.
Download for Windows
Google Play · coming soon
Installer 115 · about 216 MB · per user, no Node, no Tailscale.
Install Grok Build and sign in with your X account before you open cBuildRemote on Windows. Both sides say this plainly: without Grok Build there is nothing to control.
Link the phone to the PC
- 1
On the PC, confirm Grok Build is installed and the X account is signed in.
- 2
Install cBuildRemote for Windows and open it. It shows a QR and the same code as text you can copy.
- 3
On the phone, install the app. Scan the QR or type the code. The camera is optional: a tablet can paste the code.
- 4
Only the same X account that is signed in to Grok Build on that PC is accepted. Another account that reads the QR is refused.
- 5
One computer, one QR. That QR enrolls several phones and tablets at the same time. Each device gets its own access. Do not put two PCs on one QR.
- 6
Either side can be installed first. If the phone does not detect Windows yet, the app says so, offers this download, and lists the steps.
Revoke
Revoking one device removes that device. The others stay. Revoking the QR mints a new code and cuts every device enrolled under the old secret. That is what you do if the code leaks.
Reinstall
Uninstall removes the program and the startup shortcut, and keeps the pairing. You do not scan again. The secret is wiped only when you revoke the QR.
Start after you sign in to Windows
cBuildRemote stays in the notification area, next to OneDrive and the network icon, and it does not take a taskbar button. Closing the panel leaves it there. Unattended start is off by default. If you turn it on, the icon appears only after that Windows user signs in. The QR does not change. It does not start before login: Grok sessions, folders, and OneDrive exist only in that session, and resuming a chat opens a PowerShell there. It does not open an inbound firewall port.
The quick tunnel goes through Cloudflare
Discovery is not encrypted only between the phone and the PC. The Windows window says the same, in one line.